SPD club head

ABSTRACT

A golf-club head has a super plastically shaped crown integrally including sidewalls and a hosel connection having a hosel attachment opening. A bottom plate is welded to the crown and allows solder leakage concentrating on the lower part of the head. A super plastically shaped striking face is welded to the crown. A hosel is welded to the crown at the hosel connection.

DISCUSSION OF RELATED ART

The traditional forged component structure of a golf-club head has four pieces, a crown, a hosel, a base and a faceplate FIG. 4. The crown of the traditional four-piece crown is welded to the sidewalls so that leakage of solder wire is about 6-7 g, which concentrates on the upper part of the head, raising the head's center of gravity. This causes loss of precision and other center of weight problems that have long been unsolved in four-piece type of golf-club head. The weight distribution of a club head is generally uniform. A popular method of correcting the center of gravity is to add inserts commonly made of heavier material to the base and sidewalls of the head. Unfortunately, a typical USGA approved club has a club head weighing 7.3 oz or 206 grams so controlling club head weight distribution and the consequential sweet spot creates tolerance issues during manufacturing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of the club head.

FIG. 2 is an assembled view of the club head.

FIG. 3 is a section view of the club head.

FIG. 4 is a section view of the prior art club head.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENT

A mold uses super plastic deformation technique (SPD) to super plastically deform a crown FIG. 1, 110 of the golf-club head to integrally include sidewalls and a hosel connection 117. The hosel connection has a hosel attachment opening 115 receiving a standard cylindrical hosel 140 with precise tolerance. The crown 110 is then welded to the bottom plate 120, striking face 130 and hosel 140 to form a golf-club head. In traditional structures, the bottom is integrated with sidewalls and is then welded with the crown, striking face and hosel. The striking face 130 commonly has grooves 135 or other designs showing the sweet spot.

Welding the crown 110 with integral sidewalls to the other parts should lower the center of gravity of the head compared to the traditional component welded structure. In the present invention, the welding position FIG. 2, 210 is lowered to the lower side of the head and the bottom with an in leakage of solder 210 of about 3 g, which concentrates on the lower part of the head. Thus, 6-7 g is removed from the upper part of the head, where the crown and the side would otherwise have been welded. Overall, the net effect is to lower the head's center of gravity CG by about 1 mm compared to that of a head made in a traditional fashion. A 1 mm CG shift should substantially affect the sweet spot.

When the crown FIG. 1, 110 and sidewalls are super plastically integrally formed, the arch at the hosel connection 117 or throat portion 117 of the crown is stretched and formed as an integral part of the crown 110. The hosel 140 is commonly cylindrical having a pair of terminating ends A first end inserts into the crown on the club head and a second end attaches to the shaft. The hosel 140 is placed in the hosel receiving opening 117. The hosel member portion fitting into the club 142 is of smaller cross-section than the portion of the hosel member that does not fit into the inside of the club. The hosel is then welded to the hosel connection. After the connection welding, the shape of throat part or hosel attachment area on all heads are standardized having much smaller variances than before.

In the top portion of the hosel is a protruding ring that is larger than the hosel opening on the crown. The ring allows the hosel to rest in the opening without the hosel moving into or out of the opening. The bottom cylindrical portion of the hosel designed to connect to the crown is sized to fit into the circular opening. The bottom cylindrical portion does not need to be snugly fitted, and can have some slack. The hosel attachment area can be formed as a round protrusion drawn from and protruding from the top of the crown. The round protrusion would then have a terminating circumference. The hosel attachment area should have a terminating circumference matching the circumference of the protruding ring. During assembly, the protruding ring matches with the circumference of the hosel attachment area so that after welding and surface finish, the weld between the hosel attachment and hosel is a smooth transition and not noticeable. The protruding ring forms the outside circumference of the hosel.

The thickness of the bottom plate 120 can be greater than that of the sidewall plate thickness. The side and bottom parts of a traditional four piece head are of basically uniform thickness with a welding weight of around 22 g. But as the welding weight of the present invention is 7 g lighter than usual, the thickness of the bottom can be increased for greater moment of inertia and change in center of gravity. The increase of the bottom thickness allows uniform head thickness or alternatively a thin front striking face with a thick back of the crown to shift the center of gravity or change moment of inertia.

After welding, the club head is surface finished and then can be attached to a shaft to form the golf club. The surface finish can be prepared so that the entire connection appears as a single continuous shaft protruding from the crown.

FIG. 3 shows a section view of a club head 300 that has been sawn in half after assembly. The wider outside portion of the hosel 340 matches the circumference of the shaft. The hosel 340 is connected to the crown 310 at the hosel connection 315. A lower weld 322 attaches the bottom plate 320. On the right side 302 is depicted the other half of the club such that the two halves of the striking faces are facing each other.

FIG. 4 shows the prior art club 400 having the hosel 440 welded to the crown 410 at the welding point 415. The hosel protrudes 442 into the cavity of the club head. The bottom plate 420 is welded at a weld 422 to the crown 410.

CALL OUT LIST OF ELEMENTS

-   110 Crown -   115 Hosel Mount Aperture -   117 Hosel Mount And Arch -   120 Bottom Plate -   130 Striking Face -   135 Grooves On Face Plate -   140 Hosel Member -   142 Hosel Member Portion Fitting into Club 

1. A golf-club head comprising: a. a super plastically shaped crown integrally including sidewalls and a hosel connection having a hosel attachment opening; b. a bottom plate welded to the crown, wherein solder leakage concentrates on the lower part of the head; c. a super plastically shaped striking face welded to the crown; and d. a hosel welded to the crown at the hosel connection.
 2. The golf-club head of claim 1 wherein the hosel attachment opening is round and receives a standard cylindrical hosel.
 3. The golf-club head of claim 1 wherein the solder leakage is no more than three grams.
 4. The golf-club head of claim 1 wherein the crown and sidewalls are super plastically integrally formed to include an arch at the hosel connection.
 5. The golf-club head of claim 1 wherein the thickness of the bottom plate is greater than the sidewall plate thickness.
 6. The golf-club head of claim 1 wherein the crown, bottom plate and striking face are titanium.
 7. The golf-club head of claim 1 wherein the hosel attachment area of the crown terminates in a circumference matching the outside circumference of the protruding ring. 